GENX-1B - CLEANING,INSPECTION,AND REPAIR MANUAL

	GENX-1B CLEANING,INSPECTION,AND REPAIR MANUAL	Dated: 09/05/2022
	CIR 72-21-01 , REPAIR 001
	FORWARD FAN CONTAINMENT CASE ASSEMBLY - REPAIR - FORWARD ACOUSTIC LINER FACESHEET REPAIR

* * * FOR ALL

TASK 72-21-01-300-803

1 .

Repair for the Forward Fan Containment Case Assembly.

This procedure gives instructions to repair the fan stator forward acoustic liner (acoustic liner) by replacing the facesheet and the honeycomb. Refer to Figure 901.

The following Maximum Repairable limits apply to this repair:

NOTE:

The information below gives maximum repairable limits for the applicable Inspection sections. The paragraphs are numbered the same as the manual Inspection sections.

NOTE:

For 72-21-01, Inspection 001. Refer to TASK 72-21-01-200-801 (72-21-01, INSPECTION 001) .

(4)

Visual Inspection.

(i)

Do an inspection of the forward acoustic liner for:

Cracks:

Maximum repairable limit:

Any amount, up to an entire facesheet segment, if the fan case is not damaged.

Nicks and scratches on the face sheet:

Maximum repairable limit:

Any amount, up to an entire facesheet segment, if the fan case is not damaged.

Tears and cuts on the face sheet:

Maximum repairable limit:

Any amount, up to an entire facesheet segment, if the fan case is not damaged.

Delaminations on the face sheet:

Maximum repairable limit:

Any amount, up to an entire facesheet segment, if the fan case is not damaged.

Punctures and holes on the face sheet:

Maximum repairable limit:

Any amount, up to an entire facesheet segment, if the fan case is not damaged.

The subsequent table gives a list of the part numbers that are applicable to this repair. All part numbers are applicable to all paragraphs unless specified differently.

NOTE:

（HES）All applicable Forward fan case assembly part numbers can be repaired with CIR 72-21-01, Repair 001 as long as you have required access to perform the repair and if all repair instructions can be followed at assembled condition. Refer to Case #01995577.

Part Number(s)

Proprietary/Complex Process Statement.

(1)

None.

2 .

Tools, Equipment, and Materials.

NOTE:

You can use equivalent alternatives for tools, equipment, and consumable materials.

Tools and Equipment.

(1)

Special Tools. None.

(2)

Standard Tools and Equipment. None.

(3)

Locally Manufactured Tools.

Description

Figure

Steel Rod

902

Teflon Spatula

903

Clamping Tool

904

Consumable Materials.

Code No.

Description

C01-011

Adhesive, Paste, Two Part (paste adhesive)

C01-147

Adhesive, Structural, Liquid (liquid adhesive)

C01-155

Adhesive, Paste, Two Part (Hysol EA-9394 paste adhesive)

C01-161

Abradable Seal Material

C05-003

Marking Pens

C10-003

Fabric, Glass

C10-008

Honeycomb Core, Phenolic Reinforced Polyamid Fiber (honeycomb core)

C10-108

Brush, Disposable, Natural Bristle (brush)

C10-133

Film, Polymer FEP, Un-perforated 0.001 in. (0.03 mm) thick (FEP Film)

C10-136

Tape, Pressure Sensitive (tape)

C10-139

Gloves, White Cotton Disposable (cotton gloves)

C10-140

Gloves, Film Latex or Nylon/Polyethylene Disposable (nylon gloves)

C10-141

Abrasive Paper (120-180 grit abrasive paper)

C10-142

Film, Polyester, (Mylar), 0.002-0.004 in thick (polyester film)

C10-182

Cloth, Cleaning for Aircraft Structural (SAE-AMS 3819, BMS 15-5) (cleaning cloth)

Referenced Procedures.

70-16-00

Marking Practices

70-16-02

Temporary Marking

70-43-27

Paint - Epoxy Polyamide Coating for Composites

70-46-01

Masking and Cleaning of Epoxy and Polyester Matrix Thermosetting Composite Materials

70-46-02

Drying of Thermosetting Composite Materials

72-21-01

Inspection 001

SAE ARP 5144 Heat Application for Thermosetting Resin Curing

Expendable Parts. None.

SPD Information.

CSN

Description

Facesheet (2639M44P01) (facesheet SPD)

(1)

Locally Manufactured SPD.

Description

Figure

Splice Plate

907

Special Solutions. None.

Test Specimens. None.

3 .

Dimensional Information.

Subtask 72-21-01-220-046

Refer to Figure 906 for specified dimensions and locations.

NOTE:

The dimensional data identified within this procedure was designed using inches as the base unit of measurement for dimensional values. The conversion to millimeters is rounded to one less decimal digit than inches. For minimum dimensions converted values are rounded up. For maximum dimensions, converted values are rounded down. To avoid conversion errors, do not re-convert from millimeters to inches.

Description

Minimum In-Process Dimension

Maximum In-Process Dimension

Minimum Finish Dimension

Maximum Finish Dimension

Reference Dimension

Dim. A

0.50 in. (12.7 mm)

0.75 in. (19.0 mm)

Dim. B

0.06 in. (1.5 mm)

Dim. C

0.02 in. (0.5 mm)

4 .

Setup Information.

None.

5 .

Procedure.

Subtask 72-21-01-930-002

NOTE:

There are eight acoustic liner segments bonded to the fan case. If you find damage to the fan case, the forward acoustic liners are not repairable by this procedure.

If necessary, make the tools that follow:

(1)

Make a steel rod. Refer to Figure 902.

(2)

Make a Teflon spatula. Refer to Figure 903.

(3)

Make a clamping tool. Refer to Figure 904.

Subtask 72-21-01-220-047

Do an inspection of the acoustic liner damaged area. Refer to Figure 901, and as follows:

(1)

Remove the loose or damaged facesheet and the honeycomb material.

NOTE:

Do not extend the damaged area.

Subtask 72-21-01-350-015

(2)

Clean the acoustic liner damaged area. Refer to TASK 70-46-01-350-030 (MASKING AND CLEANING OF EPOXY AND POLYESTER MATRIX THERMOSETTING COMPOSITE MATERIALS), and as follows:

(a)

Use Composite Cleaning Method No. 4 or Composite Cleaning Method No. 5.

Subtask 72-21-01-210-002

(3)

Do a check for disbond and delamination as follows:

(a)

Tap the facesheet of the acoustic liner lightly with the steel rod and listen to the sound.

NOTE:

Different thickness of the facesheet and the fan case will make different sounds. This difference in sound does not show a disbond.

(b)

If you hear a solid click, there is no disbond or delamination.

(c)

If you do not hear a solid click, there is a disbond or delamination.

(d)

Put a mark around the areas that are disbonded or delaminated. Refer to TASK 70-16-00-350-001 (MARKING PRACTICES), and TASK 70-16-02-350-017 (TEMPORARY MARKING), and as follows:

Use a C05-003 marking pen.

(e)

Make a template of the mark around the damaged area as follows:

Make the shape of the template in a geometric shape that is easy to cut.

Subtask 72-21-01-140-006

WARNING:

DO NOT BREATHE THE PARTICLES FROM REPAIR OF COMPOSITE MATERIALS OR LET THE PARTICLES TOUCH YOU. THE PARTICLES CAN CAUSE DAMAGE, INJURY, OR IRRITATION TO YOU. USE PERSONAL PROTECTION EQUIPMENT. USE LOCAL MECHANICAL EXHAUST VENTILATION OR AN APPROVED RESPIRATOR.

Prepare the acoustic liner segment for repair as follows:

WARNING:

USE EYE PROTECTION WHEN YOU CUT MATERIAL OR PARTS. THE PARTICLES CAN CAUSE DAMAGE TO YOUR EYES.

CAUTION:

REMOVE ONLY A MINIMUM OF MATERIAL FROM THE FACESHEET. DAMAGE TO THE FACESHEET WILL MAKE THE REPAIR LARGER.

(1)

Remove the damaged area of the facesheet as follows:

(a)

Cut the acoustic liner as follows:

Cut along the mark that is around the damaged area.

Use an air driven, right angle drive grinder with a small diameter cut-off disk.

Do not cut into the honeycomb.

(b)

Use needle-nosed pliers to remove the damaged facesheet as follows:

Start at a corner or an edge and carefully pull the cut-out part of the facesheet from the acoustic liner.

(2)

If the honeycomb is damaged, remove the honeycomb down to the fan case as follows:

WARNING:

BE CAREFUL WHEN YOU USE SHARP OR POINTED TOOLS. THESE TOOLS CAN CAUSE AN INJURY TO YOU.

WARNING:

USE EYE PROTECTION WHEN YOU CUT MATERIAL OR PARTS. THE PARTICLES CAN CAUSE DAMAGE TO YOUR EYES.

CAUTION:

DO NOT CUT OR BLEND THE FAN CASE. YOU CAN CAUSE DAMAGE TO THE PART.

(a)

Use a razor knife or hand held router to cut the honeycomb the same size as the hole in the facesheet.

(b)

Use needle nosed pliers to remove the honeycomb from the repair area.

(c)

Remove all the loose and crushed material.

WARNING:

DO NOT BREATHE THE PARTICLES WHEN SANDING. THE PARTICLES CAN CAUSE DAMAGE, INJURY, OR IRRITATION TO YOU. USE PERSONAL PROTECTION EQUIPMENT. USE LOCAL MECHANICAL EXHAUST VENTILATION OR AN APPROVED RESPIRATOR.

(d)

Use C10-141 120-180 grit abrasive paper to remove the remaining honeycomb and make the surface of the fan case rough.

Subtask 72-21-01-220-048

(3)

Chamfer the edges of the facesheet for a distance of dimension A around the hole in the facesheet. Refer to Subtask 72-21-01-220-046 (paragraph 3.A, Dimensional Information), and Figure 906.

(4)

Do an inspection of the repair area and do as follows:

(a)

Do an inspection of the repair area for water or oil and do as follows:

If necessary, remove the water or oil. Refer to TASK 70-46-02-360-002 (DRYING OF THERMOSETTING COMPOSITE MATERIALS).

(b)

Do an inspection of the fan case and do as follows:

If you find damage to the fan case in the repair area, the forward acoustic liners are not repairable by this procedure.

Subtask 72-21-01-160-006

(5)

Clean the repair area as follows:

WARNING:

USE EYE PROTECTION WHEN YOU USE COMPRESSED AIR TO CLEAN, COOL, OR DRY PARTS OR TOOLS. PARTICLES CAN CAUSE AN INJURY TO YOUR EYES. DO NOT USE MORE THAN 30 PSIG (200 KPA). DO NOT POINT COMPRESSED AIR AT YOURSELF OR OTHER PERSONS.

(a)

Blow the unwanted debris from the repair area with clean, dry, compressed air that contains no oil.

Subtask 72-21-01-350-016

(b)

Clean the repair area. Refer to TASK 70-46-01-350-030 (MASKING AND CLEANING OF EPOXY AND POLYESTER MATRIX THERMOSETTING COMPOSITE MATERIALS), and as follows:

Use Composite Cleaning Method No. 4 or Composite Cleaning Method No. 5.

Subtask 72-21-01-350-017

(c)

Apply masking to the areas that you will not repair. Refer to TASK 70-46-01-350-030 (MASKING AND CLEANING OF EPOXY AND POLYESTER MATRIX THERMOSETTING COMPOSITE MATERIALS), and as follows:

NOTE:

This is done to prevent contamination from spills, drips and runs.

Use Composite Masking Method No. 3.

(d)

Apply masking to the areas that you will repair. Refer to TASK 70-46-01-350-030 (MASKING AND CLEANING OF EPOXY AND POLYESTER MATRIX THERMOSETTING COMPOSITE MATERIALS), and as follows:

NOTE:

This is done to prevent contamination until the trial fit of the facesheet and honeycomb takes place.

Use Composite Masking Method No. 4.

Subtask 72-21-01-350-018

Repair the acoustic liner damaged area. Refer to TASK 72-21-01-300-803 (paragraph 2.E., SPD Information), Figure 906, and do as follows:

(1)

Prepare the facesheet SPD for installation as follows:

(a)

Find the area of the facesheet that is the same as the cut-out area on the acoustic liner as follows:

Use the template and find the area of the facesheet that is the same as the cut-out area on the acoustic liner.

Make sure the holes of the SPD are aligned to agree with the holes of the acoustic panel.

(b)

Put a mark around the area on the facesheet to cut out. Refer to TASK 70-16-00-350-001 (MARKING PRACTICES), and TASK 70-16-02-350-017 (TEMPORARY MARKING), and as follows:

Use a C05-003 marking pen.

Subtask 72-21-01-140-007

WARNING:

(c)

Make the facesheet SPD as follows:

WARNING:

USE EYE PROTECTION WHEN YOU CUT MATERIAL OR PARTS. THE PARTICLES CAN CAUSE DAMAGE TO YOUR EYES.

Use a right-angle grinder with a cut-off disk to cut the facesheet SPD.

WARNING:

USE EYE PROTECTION WHEN YOU CUT MATERIAL OR PARTS. THE PARTICLES CAN CAUSE DAMAGE TO YOUR EYES.

Cut the facesheet SPD dimension A larger in all directions than the mark on the facesheet.

WARNING:

Use a small disk sander to chamfer the edges of the facesheet to agree with the chamfer on the acoustic liner.

Subtask 72-21-01-350-019

(2)

If necessary, prepare the honeycomb SPD for installation as follows:

WARNING:

USE EYE PROTECTION WHEN YOU CUT MATERIAL OR PARTS. THE PARTICLES CAN CAUSE DAMAGE TO YOUR EYES.

(a)

Make the honeycomb SPD. Refer to Figure 906, and as follows:

Use C10-008 honeycomb core.

Machine the honeycomb SPD to the correct thickness for the repair area.

WARNING:

BE CAREFUL WHEN YOU USE SHARP OR POINTED TOOLS. THESE TOOLS CAN CAUSE AN INJURY TO YOU.

Cut the honeycomb SPD to get the correct fit into the cut-out area in the liner segment.

Use a razor knife or grinder with a cut-off disk to cut the honeycomb SPD.

The maximum distance permitted between the facesheet and the honeycomb in the acoustic liner is dimension B.

Subtask 72-21-01-350-020

(3)

Do a trial fit of the facesheet SPD and the honeycomb SPD into the repair area as follows:

NOTE:

If the honeycomb is not to be repaired, only a trial fit for the facesheet SPD is necessary.

(a)

Remove the masking from the repair area.

(b)

Do a trial fit of the honeycomb SPD and facesheet SPD into the acoustic liner as follows:

Install the honeycomb SPD and the facesheet SPD into the repair area.

Measure the differences in contour between the facesheet SPD and the acoustic liner facesheet and do as follows:

The maximum difference permitted is dimension C.

Make sure that surface is smooth and there is no step between the two surfaces.

If the repair covers the forward edge of the perforated area of the facesheet, adjust the thickness of the honeycomb SPD to permit a change in thickness of the facesheet SPD at that location.

(c)

Remove the honeycomb SPD and facesheet SPD from the acoustic liner.

Subtask 72-21-01-350-021

(d)

Clean the repair areas of the acoustic liner and the facesheet SPD. Refer to TASK 70-46-01-350-030 (MASKING AND CLEANING OF EPOXY AND POLYESTER MATRIX THERMOSETTING COMPOSITE MATERIALS), and as follows:

Use Composite Cleaning Method No. 4 or Use Composite Cleaning Method No. 5.

(e)

Clean the honeycomb SPD. Refer to TASK 70-46-01-350-030 (MASKING AND CLEANING OF EPOXY AND POLYESTER MATRIX THERMOSETTING COMPOSITE MATERIALS), and as follows:

Use Honeycomb Cleaning Method No. 3.

Use clean C10-139 cotton gloves when you touch the clean parts.

(4)

Put the honeycomb SPD and facesheet SPD into separate clean, new plastic bags until you will use the parts.

Subtask 72-21-01-360-009

WARNING:

EPOXY RESIN AND CATALYST ARE TOXIC TO SKIN, EYES AND RESPIRATORY TRACT. SKIN AND EYE PROTECTION ARE REQUIRED. USE IN A WELL-VENTILATED AREA. WEAR CLEAN NYLON FILM, LATEX OR POLYETHYLENE DISPOSABLE GLOVES WHEN APPLYING ADHESIVE.

WARNING:

DO NOT MIX QUANTITIES MORE THAN 450 GRAMS AS DANGEROUS HEAT BUILD UP CAN OCCUR CAUSING UNCONTROLLED DECOMPOSITION OF THE MIXED ADHESIVE. TOXIC FUMES CAN OCCUR RESULTING IN PERSONAL INJURY.

CAUTION:

IF THE ADHESIVES HAVE BEEN STORED BELOW ROOM TEMPERATURE MAKE SURE THAT THE ADHESIVE IS PERMITTED TO REACH ROOM TEMPERATURE BEFORE THE CONTAINER IS OPENED. CONDENSATION CAN REDUCE THE STRENGTH OF THE ADHESIVE.

(5)

Alternative Procedure Available. Prepare the C01-011 paste adhesive to bond the honeycomb SPD and facesheet SPD to the acoustic liner as follows:

(a)

Make an estimate of the amount of C01-011 paste adhesive that will be necessary.

(b)

Mix the C01-011 paste adhesive in a clean metal or uncoated paper container.

(c)

Mix the quantities in the ratio as follows:

Part A (Resin (Thixotropic gray material)) - 100 parts by weight.

Part B (Catalyst (Liquid)) - 33 parts by weight.

(d)

Mix the resin and catalyst until there are no streaks in the adhesive.

NOTE:

The pot life of the adhesive will be approximately 30 minutes.

Subtask 72-21-01-360-010

WARNING:

EPOXY RESIN AND CATALYST ARE TOXIC TO SKIN, EYES AND RESPIRATORY TRACT. SKIN AND EYE PROTECTION ARE REQUIRED. USE IN A WELL VENTILATED AREA. WEAR CLEAN NYLON FILM, LATEX OR POLYETHYLENE DISPOSABLE GLOVES (C10-140) WHEN APPLYING THE ADHESIVE.

CAUTION:

(5).A.

Alternative Procedure. Prepare the C01-155 Hysol EA-9394 paste adhesive to bond the honeycomb SPD and facesheet SPD to the acoustic liner as follows:

(a)

Refer to the manufacturer’s instructions to mix Part A and Part B.

Subtask 72-21-01-360-011

(6)

If necessary, install the honeycomb SPD into the repair cavity as follows:

(a)

Remove the masking from the repair area.

(b)

Remove the honeycomb SPD from the plastic bag.

(c)

Use a C10-108 brush to C01-011 paste adhesive to the fan case and honeycomb SPD as follows:

Apply C01-011 paste adhesive to the fan case surface.

Rub the adhesive thoroughly on the surface. Apply a thin layer approximately 0.05 inch (1.3 mm) in thickness.

If necessary, use a Teflon spatula, Figure 903, to make the adhesive level.

Apply C01-011 paste adhesive to the bottom of the honeycomb SPD.

(d)

Put the honeycomb SPD into the hole in the acoustic liner as follows:

Mix the C01-161 abradable seal material. Follow manufacturer’s instructions, and do as follows:

Mix Part A and Part B separately to get a constant appearance.

Mix Part A and Part B thoroughly until there are no streaks.

NOTE:

The pot life of the C01-161 abradable seal material is 20 minutes.

Use a C10-108 brush to apply the C01-161 abradable seal material to the sidewalls of the repair area as follows:

Make the C01-161 abradable seal material layer approximately 0.05 inch (1.3 mm) in thickness.

Use a C10-108 brush to apply the C01-161 abradable seal material to sidewalls of honeycomb SPD as follows:

Make the C01-161 abradable seal material layer approximately 0.05 inch (1.3 mm) in thickness.

Push the honeycomb SPD into the repair area.

If necessary, use a dry C10-182 cleaning cloth to remove the unwanted C01-161 abradable seal material from the repair area.

(7)

Install the facesheet SPD as follows:

(a)

Apply the C01-011 paste adhesive as follows:

Apply the C01-011 paste adhesive to the top of the honeycomb SPD as follows:

Use a C10-108 brush.

Make the adhesive layer approximately 0.05 inch (1.3 mm) in thickness.

Apply the C01-011 paste adhesive to the chamfered areas of the acoustic liner facesheet and the inside surface and chamfered area of the facesheet SPD as follows:

Use a C10-108 brush.

Make the adhesive layer approximately 0.05 inch (1.3 mm) in thickness.

(b)

Put the facesheet SPD on the repair area and do as follows:

Make sure that the small holes in the facesheet SPD are aligned with the acoustic liner.

Make sure the chamfered area on the facesheet SPD and the acoustic liner facesheet touch on all of the tapered surfaces.

Use a dry C10-182 cleaning cloth to remove the unwanted paste adhesive.

CAUTION:

HOLD THE FAN CASE IN THE REPAIR AREA BEFORE YOU APPLY THE WEIGHT. IF YOU DO NOT DO THIS, DAMAGE TO THE ACOUSTIC LINER CAN OCCUR.

(c)

Put a layer of C10-133 FEP film on the repair area and do as follows:

Use a weight, turnbuckle spreader bar, or clamping tool to apply the same pressure on all of the repair area. Refer to Figure 905.

NOTE:

For example, a bag that contains dry sand can be used.

The quantity of weight necessary will depend on the repair area.

Apply a pressure of 2-5 psi (14-34 kPa) to the repair area.

NOTE:

(HES) Vacuum bagging the repair area can be used as an alternate method of securing the repair area in place while during the cure cycle. I recommend you refer to SPM 70-46-03 VACUUM BAGGING OF THERMOSETTING COMPOSITE REPAIRS for best practices for vacuum bagging. Also, the use of caul plates is recommended to help distribute the vacuum load more evenly across the repair area. Refer to Case #01900956.

NOTE:

(HES) You can use C01-189 (Rubber, Silicone Sheet, molded (GE Spec A12F18A2)), Rubber, Silicone Sheet, molded, 0.125 inch (3.2 mm) thick) caul plate. Refer to Case #01907570.

(d)

Use a dry C10-182 cleaning cloth and a 0.045-0.055 inch (1.15-1.39 mm) diameter drill rod to remove the unwanted adhesive from the facesheet surface and from the small holes and as follows:

Move the weight and film as necessary while you do this step.

WARNING:

EPOXY RESIN AND CATALYST ARE TOXIC TO SKIN, EYES AND RESPIRATORY TRACT. SKIN AND EYE PROTECTION ARE REQUIRED. USE IN A WELL VENTILATED AREA. WEAR CLEAN LATEX, NYLON FILM OR POLYETHYLENE DISPOSABLE GLOVES WHEN MIXING OR APPLYING ADHESIVE.

WARNING:

DO NOT MIX QUANTITIES GREATER THAN 450 GRAMS AS DANGEROUS HEAT BUILD UP CAN OCCUR CAUSING UNCONTROLLED DECOMPOSITION OF THE MIXED ADHESIVE. TOXIC FUMES CAN OCCUR RESULTING IN PERSONAL INJURY.

(e)

If necessary, fill the gap between the two acoustic liners as follows:

Make sure that there is a distance of 0.00-0.28 inch (0-7.1 mm) between the acoustic liners.

Prepare the C01-155 Hysol EA-9394 paste adhesive as follows:

Make an estimate of the amount of C01-155 Hysol EA-9394 paste adhesive that will be necessary.

Mix the adhesive as instructed by the manufacturer.

Use a Teflon spatula to fill the gap between acoustic liners with the mixed C01-155 Hysol EA-9394 paste adhesive.

(f)

Cure the repair area as follows:

Keep the fan case supported and do not remove the FEP film when there is an increase of pressure on the acoustic liner.

Keep the constant pressure on the repair area.

Subtask 72-21-01-360-012

Alternative Procedure Available. Cure the paste adhesive for a minimum of 5 days at a temperature range of 65 to 85°F (18 to 29°C).

Subtask 72-21-01-360-013

3.A.

Alternative Procedure. Cure the paste adhesive for a minimum of 1 hour at a temperature range of 140 to 160°F (60 to 71°C). Refer to SAE ARP 5144 Heat Application for Thermosetting Resin Curing.

(g)

Remove the pressure and the FEP film from the repaired area.

(h)

Remove all the masking material.

Subtask 72-21-01-160-007

WARNING:

Clean the acoustic liner after repair as follows:

CAUTION:

DO NOT DRILL INTO THE HONEYCOMB. THIS WILL CAUSE DAMAGE TO THE HONEYCOMB.

(1)

Drill to remove the remaining adhesive from the holes in the facesheet as follows:

(a)

Use a pin vise and a 0.045-0.055 inch (1.15-1.39 mm) diameter drill bit.

Subtask 72-21-01-140-010

WARNING:

(2)

Use C10-141 120-180 grit abrasive paper to remove the unwanted adhesive from the repair area.

Subtask 72-21-01-220-049

Do an inspection of the facesheet repaired area as follows:

(1)

Do an inspection of the bond line around the repair area as follows:

(a)

Voids and loose adhesive not permitted.

Subtask 72-21-01-210-003

(2)

Do a check of the facesheet for delamination. Refer to Subtask 72-21-01-210-002 (paragraph 5.B.(3)).

Subtask 72-21-01-220-050

(3)

Do an inspection of the contour as follows:

(a)

Measure the differences in contour between the facesheet SPD and the acoustic liner facesheet. The maximum difference permitted is 0.020 inch (0.50 mm).

(b)

Make sure that the surface is smooth and there is no step between the two surfaces.

Subtask 72-21-01-350-022

NOTE:

(HES) If a facesheet/honeycomb repair is performed on the FAT (Forward Acoustic Treatment) and does not affect any of the six splice plates, there is no need to replace any of the splice plates. The reference to four (4) 0.088-0.108 inch diameter holes described in GEnx-1B CIR 72-21-01, Repair 001, Figure 907 are for references only - can be used to aid in replacing damaged splice plates. A future revision of this repair will clearly identify them as "Reference Only". These holes are not to be drilled into the FAT facesheet. Once damaged splice plates are replaced, you should drill the acoustic patten into the replaced splice plate using a 0.045-0.055 inch diameter drill bit per paragraph 5.H. Refer to Case #02003674.

If necessary, install the splice plate SPD on the repair area. Refer to Figure 907 and as follows:

(1)

Apply masking to the areas that you will not repair. Refer to TASK 70-46-01-350-030 (MASKING AND CLEANING OF EPOXY AND POLYESTER MATRIX THERMOSETTING COMPOSITE MATERIALS), and as follows:

NOTE:

This is done to prevent contamination from spills, drips and runs.

(a)

Use Composite Masking Method No. 3.

Subtask 72-21-01-140-012

WARNING:

(2)

If necessary, remove the damaged splice plate as follows:

CAUTION:

DO NOT SAND INTO THE ACOUSTIC PANEL. DAMAGE TO THE PART CAN OCCUR.

(a)

Use an air driven, right angle grinder with a sanding disk.

WARNING:

(b)

Blow the unwanted debris from the repair area with clean, dry, compressed air that contains no oil.

Subtask 72-21-01-350-023

(c)

Clean the repair areas of the acoustic liner. Refer to TASK 70-46-01-350-030 (MASKING AND CLEANING OF EPOXY AND POLYESTER MATRIX THERMOSETTING COMPOSITE MATERIALS), and as follows:

Use Composite Cleaning Method No. 4 or Use Composite Cleaning Method No. 5.

Subtask 72-21-01-350-024

(3)

Make a splice plate SPD as follows:

(a)

Put a layer of C10-142 polyester film on a work table.

WARNING:

USE EYE PROTECTION WHEN YOU CUT MATERIAL OR PARTS. THE PARTICLES CAN CAUSE DAMAGE TO YOUR EYES.

(b)

Cut four plies of C10-003 glass fabric of sufficient size for the repair area.

(c)

Put the C10-003 glass fabric on the C10-142 polyester film.

Subtask 72-21-01-360-014

WARNING:

DO NOT MIX QUANTITIES GREATER THAN 450 GRAMS AS DANGEROUS HEAT BUILD UP CAN OCCUR CAUSING UNCONTROLLED DECOMPOSITION OF THE MIXED ADHESIVE. TOXIC FUMES CAN OCCUR RESULTING IN PERSONAL INJURY.

CAUTION:

IF THE ADHESIVE WAS STORED BELOW ROOM TEMPERATURE, LET THE ADHESIVE TEMPERATURE INCREASE TO ROOM TEMPERATURE BEFORE YOU OPEN IT. CONDENSATION WILL DECREASE THE STRENGTH OF THE ADHESIVE.

(d)

Prepare the C01-147 liquid adhesive, and do as follows:

Make an estimate of the quantity of C01-147 liquid adhesive that you will use.

Use a clean metal or paper container that has no wax.

Weigh sufficient quantities of each component to the proportions that follow:

Part A (adhesive)- 100 units.

Part B (catalyst) - 30 units.

Mix the adhesive components until there are no streaks of the two components.

NOTE:

The pot life of the mixed adhesive is approximately 75 minutes.

(e)

Rub the C01-147 liquid adhesive on the C10-003 glass fabric with a new and clean C10-108 brush.

(f)

Put a second piece of new C10-142 polyester film on top of the C10-003 glass fabric and C01-147 liquid adhesive.

(g)

Use the Teflon spatula to push the C01-147 liquid adhesive into the C10-003 glass fabric until the two sides are fully wet with C01-147 liquid adhesive.

(h)

Use the Teflon spatula to remove all the caught air and the unwanted liquid adhesive.

(i)

Remove one side of the polyester film or vacuum bag film from the first ply.

(j)

Apply a layer of C01-147 liquid adhesive of approximate 0.010 inch (0.25 mm) in thickness on the repair area as follows:

Use a new, clean C10-108 brush to apply the C01-147 liquid adhesive.

(k)

Put the C10-003 glass fabric ply with the side that you removed from the C10-142 polyester film on the repair area.

(l)

Remove the top piece of polyester film or vacuum bag film from the first C10-003 glass fabric ply.

Subtask 72-21-01-360-015

(m)

Apply a layer of C01-147 liquid adhesive of approximate 0.010 inch (0.25 mm) in thickness on the first piece of C10-003 glass fabric as follows:

Use a new, clean C10-108 brush to apply the C01-147 liquid adhesive.

Use the Teflon spatula to remove all the caught air and make the C01-147 liquid adhesive smooth.

Subtask 72-21-01-350-027

(n)

Put the next piece of C10-003 glass fabric on the previous ply as follows:

Remove the polyester film or the vacuum bag film from one side of the next piece of C10-003 glass fabric.

Use the Teflon spatula to remove all the caught air and make the C01-147 liquid adhesive smooth.

Remove the polyester film from the second side of the ply.

Subtask 72-21-01-360-016

(o)

Do Subtask 72-21-01-360-015 (paragraph 5.G.(3)(m)) thru Subtask 72-21-01-350-027 (paragraph 5.G.(3)(n)) again for the remaining plies.

Subtask 72-21-01-360-017

(p)

Alternative Procedure Available. Let the mixed adhesive cure for 3-5 days at a minimum temperature of 65°F (18°C).

Subtask 72-21-01-360-018

WARNING:

USE THERMAL GLOVES WHEN YOU MOVE OR TOUCH HOT OR COLD PARTS. HOT OR COLD PARTS CAN CAUSE INJURY.

(p).A.

Alternative Procedure. Let the mixed adhesive cure for 8 hours at a minimum temperature of 65°F (18°C) followed by a minimum of 1 hour at a temperature range of 180 to 200°F (82 to 93°C). Refer to SAE ARP 5144 Heat Application for Thermosetting Resin Curing.

(q)

Remove the polyester film.

Subtask 72-21-01-140-011

WARNING:

(r)

Sand the slice plate SPD to get a smooth matte finish as follows:

NOTE:

A matte finish has a dull appearance with no brightness, luster, or gloss.

Use C10-141 120-180 grit abrasive paper.

Subtask 72-21-01-160-008

WARNING:

(s)

Remove the dust from the SPD facesheet with clean, dry, compressed air that contains no oil.

Subtask 72-21-01-350-026

(4)

Remove all the masking material from the repair area.

Subtask 72-21-01-350-032

Drill an acoustic pattern into the splice plate at the repair area as follows:

(1)

Drilling must penetrate the splice plate and underlying facesheet. Refer to Figure 908 and do as follows:

(a)

Apply C10-136 tape to the facesheet and adjacent areas to protect the facesheet from the drill contact damage during the repair.

(b)

Use a drill bit of 0.045-0.055 inch (1.15-1.39 mm) in diameter.

(c)

Install the drill bit into the cordless drill until only 0.125-0.145 inch (3.18-3.68 mm) sticks out.

(d)

Change the drill bit after drilling 250 holes to reduce the risk of drill breakage.

(e)

Splice plate holes do not have to be aligned with the pre-existing holes on the facesheet, however they must follow the hole pattern. Refer to Figure 908.

NOTE:

The acoustic hole pattern required for Figure 908 can be marked on the C10-136 tape as a template to facilitate locating the drilled holes.

(f)

Drill the first hole and check the depth to make sure that the drill bit goes through the splice plate and facesheet only. Do not drill into the honeycomb below.

(g)

Drill the holes that remain. Keep the drill level and straight.

(h)

Do a visual inspection of the drill bit after each hole is drilled. If the bit breaks, do not continue drilling holes and as follows:

If the drill bit can be removed, do as follows:

Remove the broken bit with pliers.

If the broken drill bit cannot be removed with pliers and/or if the bit breaks and falls into an underlying honeycomb cell, do as follows:

Push the bit through the hole into the underlying honeycomb cell.

Temporarily mark the hole so that the location in the hole pattern is not lost.

Inject C01-147 liquid adhesive into the same hole until the resin fills the underlying honeycomb cell and weeps out of the adjacent holes. Temporarily plug adjacent weep holes with C10-136 tape, so resin does not run onto adjacent surfaces. Continue injecting resin until no more resin weeps from the adjacent holes. Plug the hole used for resin injection.

Subtask 72-21-01-350-033

Alternative Procedure Available. Let the resin cure for 3-5 days at a minimum temperature of 65 °F (18 °C).

Subtask 72-21-01-350-034

d.A.

Alternative Procedure. Let the resin cure for 8 hours at a minimum temperature of 65 °F (18 °C) followed by a minimum of 1 hour at a temperature of 180 °F (82 °C) to 200 °F (93 °C).

Subtask 72-21-01-220-066

(2)

Do a visual inspection of the drilled holes as follows:

(a)

Remove the C10-136 tape.

(b)

Make sure that all the drilled holes are horizontally and vertically in line.

(c)

Do a visual inspection to determine whether the holes have been drilled through the facesheet and closeouts. Refer to Figure 908.

Subtask 72-21-01-380-001

Paint the repair area. Refer to TASK 70-43-27-380-001 (PAINT - EPOXY POLYAMIDE COATING FOR COMPOSITES).

NOTE:

(HES) A heat lamp is an acceptable alternative to an oven to cure the paint applied to the repaired area on the Forward Acoustic Liner facesheet per GEnx-1B CIR 72-21-01, Repair 001. Be sure you have equipment to monitor the temperature (175° ± 10°F (79° ± 6°C)) in the painted area for the cure cycle (60-90 minutes) to ensure a full paint cure. Refer to Case #01892053.

Subtask 72-21-01-220-051

Do an inspection of the paint as follows:

(1)

Do an inspection for grit as follows:

(a)

Any number is permitted. The total collected amount must be 0.062 x 0.062 x 0.010 inch (1.57 x 1.57 x 0.25 mm) in height in a 1.0 sq in. (645 sq mm) area.

(2)

Do an inspection for seeds as follows:

(a)

Any number is permitted. The total collected amount must not be more than 0.062 x 0.062 x 0.010 inch (1.57 x 1.57 x 0.25 mm) high in a 1.0 sq in. (645 sq mm) area.

(3)

Do an Inspection for runs as follows:

(a)

Runs must not be more than 0.010 inch (0.25 mm) above the coating surface.

(4)

Do an inspection for craters as follows:

(a)

Any number is permitted. The total collected amount must not be more than 0.125 x 0.125 x 0.010 inch (3.17 x 3.17 x 0.25 mm) in depth in a 1.0 sq in. (645 sq mm) area.

(5)

Do an inspection for blisters as follows:

(a)

None permitted.

Subtask 72-21-01-380-002

(6)

If the paint does not agree with the inspection limits, paint the facesheet again. Refer to TASK 70-43-27-380-001 (PAINT - EPOXY POLYAMIDE COATING FOR COMPOSITES).

* * * FOR ALL